Help me undestand

[KennethM]

35 minutes ago, alpha2 said:

I still sometimes use a rotary cutter for long straight cuts, especially with thin leather. It cuts downward instead of pulling the leather. It's also easy to see if the blade isn't vertical. Not that good for corners, though. 

For sure,I didn't think they would be good for corners

[battlemunky]

Make two kiradashi if you do @KennethM, you don't want to use the leather one for wood or else you'll be busy fixing the edge all the time. You want your leather knife edges (of all kinds) polished mirror smooth and scary sharp.

[Sheilajeanne]

Yeah, I still laugh at that story about the guy who decided to test the edge of the leather worker's round knife, after he'd cut out a holster for him... 

 

Edited September 29, 2018 by Sheilajeanne

[Big Sioux Saddlery]

I don't remember seeing that thread before ("Things I've Learned From Leather Working")  Lots of goodies in there, and I've done them all!  I have put a barrier up in my shop to prevent the public from going back into my work space.  If someone wants to see that area, I'm happy to give them a tour, but I don't want people, (especially children whose parents are constantly oblivious to what their children are doing at any given time), wandering back there and picking up sharp objects. 

[Mattsbagger]

I trace acrylic templates with a scratch awl. Then use a metal straight edge and rotary cutter on straight cuts and a clicker knife or exacto on other lines. I find holding a template with one hand and cutting around it with another impossible for me.

[zuludog]

6 minutes ago, Mattsbagger said:

I trace acrylic templates with a scratch awl. Then use a metal straight edge and rotary cutter on straight cuts and a clicker knife or exacto on other lines. I find holding a template with one hand and cutting around it with another impossible for me.

Yes, that's a good idea; it's what scratch awls were made for, hence the name

[Matt S]

There's a lot of great suggestions in this thread and I'm not going to repeat any of them, but I think one thing that hasn't been mentioned yet is that leather, frustratingly, can move once it's cut. Consider that a cow is, roughly speaking, spherical (ask a physicist if you're in doubt!) and a hide of leather is flat. When the tanner flattens it out they use heat, pressure and moisture to achieve this effect, which is pretty successful. However the residual stresses from this, added to the grain patterns and directions from when it was a beast, can make some odd and frustrating things happen -- but only once the piece is liberated from the hide, and those stresses are no longer held in check. As a smith and woodworker I'm sure the idea will be familiar to you. These stresses and odd grain are most pronounced in the pieces of hide which have changed the most to become flat -- neck, leg, belly, chest etc. -- and I suspect are most pronounced on the smaller beasts like goat, sheep and deer, though I work mainly in cow so don't have enough empirical evidence to say that for certain.

It's most obvious when cutting a straight strap off a side -- you can mark a line with an engineer's straightedge, cut it exactly, then tear out your hair at why the strap has a few millimetres' bow along its length. Other odd things can happen from grain. I have a bifold wallet I made earlier this year which doesn't fold straight but at an angle. I was trying to be clever and managed to squeeze the back from the neck of a side I had. The only way it would fit was at an angle. It was only once I'd finished the wallet I realised that that angle was the very same angle at which it naturally folds. Guess how clever I feel now!

Sometimes, when a specific dimension is needed, I cut it from the hide oversized and then trim or sand to the exact size, or to match another component as needed. This, with careful selection of where I cut the pieces, usually eliminates the problem.

[battlemunky]

lol

Dr: Hughes: Just approximate the chicken to be a sphere.

Good points @Matt S!

[KennethM]

7 hours ago, Matt S said:

There's a lot of great suggestions in this thread and I'm not going to repeat any of them, but I think one thing that hasn't been mentioned yet is that leather, frustratingly, can move once it's cut. Consider that a cow is, roughly speaking, spherical (ask a physicist if you're in doubt!) and a hide of leather is flat. When the tanner flattens it out they use heat, pressure and moisture to achieve this effect, which is pretty successful. However the residual stresses from this, added to the grain patterns and directions from when it was a beast, can make some odd and frustrating things happen -- but only once the piece is liberated from the hide, and those stresses are no longer held in check. As a smith and woodworker I'm sure the idea will be familiar to you. These stresses and odd grain are most pronounced in the pieces of hide which have changed the most to become flat -- neck, leg, belly, chest etc. -- and I suspect are most pronounced on the smaller beasts like goat, sheep and deer, though I work mainly in cow so don't have enough empirical evidence to say that for certain.

It's most obvious when cutting a straight strap off a side -- you can mark a line with an engineer's straightedge, cut it exactly, then tear out your hair at why the strap has a few millimetres' bow along its length. Other odd things can happen from grain. I have a bifold wallet I made earlier this year which doesn't fold straight but at an angle. I was trying to be clever and managed to squeeze the back from the neck of a side I had. The only way it would fit was at an angle. It was only once I'd finished the wallet I realised that that angle was the very same angle at which it naturally folds. Guess how clever I feel now!

Sometimes, when a specific dimension is needed, I cut it from the hide oversized and then trim or sand to the exact size, or to match another component as needed. This, with careful selection of where I cut the pieces, usually eliminates the problem.

Thoroughly enjoyed reading this and it made sense .Being new to leather I been trying to use every peice possible .I have noticed some of the I guess weapons or wrinkles tend to not work well.I imagine maybe higher end leather works better and is easyier to deal with.

[KennethM]

I just wanted to thank everyone for the replies..All info is great and leatherwork already improving from minor adjustments